Swim Pace Calculator
Calculate swim pace per 100m or 100yd, or estimate finish time for any swimming distance including pool events and triathlon swims.
About the Swim Pace Calculator
Whether you are training for a triathlon, competing in pool events, or simply tracking your open-water swims, knowing your pace per 100 metres is the fundamental metric of swimming performance. Unlike running where pace per kilometre or mile is common, swimming uses pace per 100 metres (or 100 yards in the United States) because that is the standard lap distance in competitive swimming and the unit used for training sets.
Our swim pace calculator works in both directions: enter your pace per 100m to get your projected finish time at any distance, or enter a finish time for a known distance to calculate your average pace. This is useful for planning race-day pacing strategy, setting training targets, or converting between different race distances to compare performances.
Pace consistency is one of the most important skills in competitive swimming and triathlon. Going out too fast in an open-water swim leads to lactic acid buildup and a significant slowdown in the back half of the race. Understanding what pace corresponds to your goal finish time — and then training to sustain that pace — is the foundation of effective swim training.
Swimming for Triathlon: Pacing Strategy
Triathlon swim legs demand a different approach to pacing than pure pool events. In pool swimming, you push off the wall every 25 or 50 metres, getting a speed boost that masks your true open-water pace. In open water — especially in races like Ironman (3.8km) or Olympic distance (1.5km) — there are no walls, turns, or push-offs. Your open-water pace is typically 8–12 seconds per 100m slower than your equivalent pool pace.
Sighting — lifting your head to find the course buoys — is essential but slows you down and disrupts your stroke. Experienced triathletes sight every 6–10 strokes. Sighting adds approximately 5–10 seconds per 100m to your open-water time. Currents, chop, waves, and the initial mass-start chaos also affect pacing. When planning a triathlon swim target, always use your realistic open-water pace rather than your pool best.
The swim is the shortest leg of a triathlon in terms of time but can be the most anxiety-inducing for non-competitive swimmers. Pacing conservatively in the swim preserves energy for the bike and run. Research suggests that in Ironman triathlons, athletes who swim slower than their pool-equivalent pace and save energy tend to run faster off the bike than those who push the swim. Starting conservatively, settling into rhythm, and finishing the swim slightly stronger than you started is a well-validated pacing strategy.